浅谈建筑结构的屋面防水

正一、建筑屋面防水的种类、性能特点以及适用范围建筑屋面防水是靠材料阻断水的通路,以达到防水的目的或增加抗渗漏的能力,如卷材防水、涂膜防水、混凝土及水泥砂浆防水等。建筑屋面防水依据不同的材料种类一般分为柔性防水屋面和刚性防水屋面。在实际施工过程中,一般都采用柔刚结合的防水模式,使建筑屋面防水的耐久性及抗渗漏能力大大提高。(一)柔性防水屋面:以沥青、高分子等柔性卷材材料铺设和粘结或将高     

刚性屋面渗漏的原因及防水措施

根据刚性屋面渗漏水现象，就常用刚性屋面的防水措施，结合相关技术文献，在实践的基础上。本文提出刚性屋面防水的技术路线、材料基础、设计前提、施工关键，同时加强维护管理．目的在于改善屋面防水质量，提高刚性屋面的防水技术，通过实践，屋面渗漏率有了较大幅度的下降，屋面的防水质量大幅度提高。     

屋面防水工程的质量问题分析及防治措施

屋面防水在工程中是一个重要的分部项目。因设计和施工等原因,造成屋面渗漏现象较普遍。每年因屋面防水处理造成很大的经济损失。因此,如何从选材、设计、施工及管理维护诸多方面加强防水工程质量,确保建筑工程质量及使用寿命,是一个重要课题。详细阐述了屋面防水的类型,分析了卷材屋面和刚性屋面防水工程中的主要问题,及影响防水工程质量的诸多因素,并分别从材料选择、设计、施工和管理方面提出屋面防水质量的控制措施。     

屋面防水施工要点

本文介绍不同地区气候条件下，各种屋面防水类型的选择、新型防水材料再生胶实用范围、不同防水屋面基本作法及施工要点、常用防水建筑材料的配制，特别还对卷材防水屋面特殊部位做法进行了详细的论述。     

倒置式复合防水屋面设计与施工

介绍倒置式复合防水屋面的构造特性、设计要点和施工技术，该屋面是传统卷材防水屋面在施工工艺上的改进。通过工程实例的分析证实倒置式复合防水屋面是一种施工简便、构造合理、造价低的防水方法，在工程上应用是完全可行的，并具有良好的社会经济效益。     

试论屋面防水工程质量监控

确保屋面防水工程质量,应当提高屋面防水设计质量;严格按照现行技术标准及环境条件选材;控制屋面防水施工质量;加大屋面防水工程研究力度,加强防水工程管理.     

城市住宅的屋面防水

主要通过对几种屋面防水方案的分析,指出适合城市住宅的屋面防水的发展趋势。     

屋面防水工程存在问题及对策

本文针对屋面防水工程存在的问题,分析了房屋建筑中常用的柔性防水屋面和刚性防水屋面存在问题的原因,探讨了解决屋面防水工程质量问题的对策,对其进行研究有重要意义。     

建筑屋面渗漏原因及防治措施

建筑屋面在建筑设计和施工中占有十分重要的地位,一旦屋面防水出现问题导致渗漏,将给建筑使用者带来极大的不便。文章通过对屋面设计、材料、施工、管理四个因素对建筑屋面渗漏的原因进行分析,并在此基础上提出相应的防治措施,进而明确建筑屋面防水的重要性。     

对屋面防水设计的几点启示——从某办公大楼屋面大面积漏雨谈起

屋面设计是建筑设计的主要部分,屋面防水更是保证建筑使用功能的关键措施之一。本文通过工程实例,对国外某办公大楼屋面漏雨的原因,从气候、环境、材料、力学等方面进行分析,针对屋面防水设计中的若干问题,提出了几点看法。     

Mechanical analysis of roof stability under nonlinear compaction of solid backfill body

Based on the compaction characteristic test and the nonlinear compaction deformation characteristics of backfill material, this paper applies the theory of nonlinear elastic foundation of thin plate to establish a mechanical model of backfill body and roof in solid dense backfill coal mining. This study critically analyses the deflection equation of the roof by the energy method, derives the conditions of roof breakage and combined with concrete engineering practice analyses, determines roof movement regularity and stability in solid dense backfill mining. Analysis of the engineering practice of the 13,120 backfill panel of Pingmei 12# mine shows the theoretical maximum of roof convergence in backfill mining to be415 mm which is in significant agreement with the measured value. During the advancing process of solid backfill mining at the panel, the maximum tensile stress on the roof is less than its tensile strength which does not satisfy the conditions for roof breakage. Drilling results on the roof and ground pressure monitoring show that the integrity of roof is strong, which is consistent with the theoretical calculations described in this study. The results presented in the study provide a basis for further investigation into strata movement theory in solid dense backfill mining.     

单体支柱工作面顶板动态的监报

本文提出顶板动态监报应包括回采工作面局部冒顶的监报及顶板来压的预报这两个方面的观点。初步给出了局部冒顶监报指标的确定方法;重点探索了采用回采工作面来压综合判断指标来预报顶板来压的可能性。文中所给的回采工作面局部冒顶的监报指标及顶板来压预报指标所采用的系数,基于现场统计资料,或现场经验的数学处理结果。     

基于小波域的图像增强算法

针对图像边缘增强和滤噪的矛盾,提出了符合视觉特性的基于小波域的图像增强算法.将图像的小波变换结果看成一幅图像,则在空域中的阶跃边,在小波域的高频通道中表现为屋脊边,而空域中的屋脊边,在小波域高频通道中表现为成奇对称的屋脊边缘对.在高频通道中,用高斯函数或升余弦函数拟合屋脊边,用正弦函数拟合屋脊边对.通过修改拟合函数的参数来改变其形状,从而使反变换回来的图像的边缘斜率提高,进而达到图像增强的目的.由于在对屋脊边的识别中采用了方向信息测度,使算法能很好地处理边缘增强和滤噪的矛盾.分别对测试图像和实际图像进行处理,并与传统的高通滤波方法进行了对比,实验结果表明,本文提出的方法具有更好的视觉效果.     

Influence of Lithological Characters of Coal Bearing Formation on Stability of Roof of Coal Seams

Lithology is one of the important factors influencing the stability of roof of coal seams. In order to investigate this, the phenomenon of underground pressure and distribution of pressure were studied by using the local observation and simulation test with similar materials. The observation results show that the distance of initial weighting and periodic weighting of the mudstone roof is shorter than that of sandstone roofs. The sandstone roof with a high strength has a longer distance of initial weighting and periodic weighting, the abutment stress on the working face is big and the height of caving and fracture zone is high. The peak point of abutment stress in the sandstone roof is near to the working face and the pressure bump is inclined to occur. The result is contrary to that in case of the mudstone roof with a low strength. While in the transition zone of nipped sandstone, roof rock-mass is broken and is poor in stability, therefore, it is difficult to hold the roof.     

Investigation of factors influencing roof stability at a Western U.S.longwall coal mine

The coal mine roof rating(CMRR) was developed to bridge the gap between geological variation in underground coal mines and engineering design. The CMRR accounts for the compressive strength of the immediate roof, the shear strength and intensity of any discontinuities present, and the moisture sensitivity of the immediate roof. The CMRR has been widely used and validated in Eastern US coal mines, but it has seen limited application in the Western US. This study focuses on roof behavior at a Western coal mine(Mine A). Mine A shows significant lateral geological variation, along with localized faulting and a laterally extensive sandstone channel network. The CMRR is not used to predict roof instability at the mine. It is, therefore, hypothesized that there are other factors that are correlated with roof instability in underground coal mines that could potentially also be considered in conjunction with the CMRR.This hypothesis was tested by collecting 30 CMRR measurements at Mine A. At each measurement location, a binary record of the roof condition(stable or unstable) was made, and other parameters such as depth of cover, presence of faulting, and sandstone channels were also recorded. ANOVA tests showed that the CMRR values and the roof conditions were not strongly correlated, indicating that the CMRR input criteria are not fully predictive of roof stability at this mine. The CMRR values showed statistically significant correlations(p less than 0.05) with faulting as well as with location at an intersection. For areas that had previously experienced roof fall but were currently stable, faulting was correlated with roof condition(p less than 0.05) only when the condition was classified as unstable.     

Quantification of ventilation enhancement using the Eye CAN roof support

Convergence of roof and floor in underground mine openings is a common occurrence. This convergence not only adversely affects the ability of workers, equipment and supplies to travel through the mine, it also reduces the effectiveness of the mine ventilation system, which is essential for the dilution of methane gas and airborne respirable dust. While installing secondary standing supports to control floor and roof convergence, such supports, by nature, partially obstruct a portion of the airway. These added obstructions inhibit the ability of the ventilation system to operate as efficiently as it could by increasing the resistance in and reducing the cross-sectional area of the airway. This study introduces and demonstrates the benefits of The Eye CAN~(TM) standing roof support, which controls floor and roof convergence and is less obstructive to air flow than conventional wooden cribs. Laboratory findings show that the normal resistance of a supported lined airway is reduced by using this new product from Burrell Mining Products, Inc., while providing the same roof support characteristics of an established product—The CANò. Load vs. displacement curves generated from laboratory tests demonstrated that this new product behaves with the same roof support characteristics as others in The CAN product family. Ventilation data gathered from a simulated mine entry was then used for computational fluid dynamics(CFD) modeling.The CFD analysis showed an improvement with The Eye CAN vs. other accepted forms of standing roof support. This proof-of-concept study suggests that, when using this new product made by Burrell Mining Products, Inc., not only will the convergence from the roof and floor be controlled, but airway resistance will also be reduced.     

构造应力对煤层顶板稳定性影响的数值分析

煤层顶板垮落是煤矿生产常见的灾害,煤层顶板稳定性预测是防治顶板事故的关键技术措施。构造应力是影响煤层顶板稳定性的重要因素之一。利用FLAC3D软件,分析在构造应力的影响下煤层项板在采动过程中的变形破坏特征,以及不同侧压条件下煤层顶板的移动规律。结果表明,顶板破坏在岩梁中部是由下向上发展的,在一定的条件下,随着水平构造应力的增大,顶板破坏范围逐步减小,顶板岩层的位移逐步减小。     

屋顶节能设计探讨

屋顶作为建筑物外围护结构之一,在建筑节能方面具有重要作用.通过对平屋顶、坡屋顶、屋顶绿化、蓄水屋顶、可控性玻璃屋顶等的节能设计探讨,分析了屋顶节能的有关问题,以求在造型美观的前提下,更好地达到建筑节能的目的.     

Coal pillar design when considered a reinforcement problem rather than a suspension problem

Current coal pillar design is the epitome of suspension design.A defined weight of unstable overburden material is estimated, and the dimensions of the pillars left behind are based on holding up that material to a prescribed factor of safety.In principle, this is no different to early roadway roof support design.However, for the most part, roadway roof stabilisation has progressed to reinforcement, whereby the roof strata is assisted in supporting itself.This is now the mainstay of efficient and effective underground coal production.Suspension and reinforcement are fundamentally different in roadway roof stabilisation and lead to substantially different requirements in terms of support hardware characteristics and their application.In suspension, the primary focus is the total load-bearing capacity of the installed support and ensuring that it is securely anchored outside of the unstable roof mass.In contrast, reinforcement recognises that roof de-stabilisation is a gradational process with ever-increasing roof displacement magnitude leading to ever-reducing stability.Key roof support characteristics relate to such issues as system stiffness, the location and pattern of support elements and mobilising a defined thickness of the immediate roof to create(or build) a stabilising strata beam.The objective is to ensure that horizontal stress is maintained at a level that prevents mass roof collapse.This paper presents a prototype coal pillar and overburden system representation where reinforcement, rather than suspension, of the overburden is the stabilising mechanism via the action of in situ horizontal stresses.Established roadway roof reinforcement principles can potentially be applied to coal pillar design under this representation.The merit of this is evaluated according to failed pillar cases as found in a series of published databases.Based on the findings, a series of coal pillar system design considerations for bord and pillar type mine workings are provided.This potentially allows a more flexible approach to coal pillar sizing within workable mining layouts, as compared to common industry practice of a single design factor of safety(Fo S) under defined overburden dead-loading to the exclusion of other relevant overburden stabilising influences.     

Breaking mechanism and control technology of sandstone straight roof in thin bedrock stope

The key problem to be solved urgently is how to avoid the occurrence of support break-off and water inrush in the stoping of sandstone straight roof under the action of load transfer in unconsolidated aquifer. For this reason, taking the thin bedrock 1602(3) working face of Huainan(the middle part of Anhui Province) Panyi Coal Mine as the engineering background, this study establishes the stope mining model by using the discrete element UDEC software and the mathematics mechanical model of the support load,and analyzes the reason of support crushing and decides to re-mining the working face by using the compulsive roof caving method. It is concluded that when the working face of sandstone straight roof is broken, the ‘‘voussoir beam" structure cannot be formed and acts on the support in the form of cantilever beam, but only when it falls to the high key stratum can the ‘‘voussoir beam" structure be formed and at this point, at this time, the bracket bears the weight of the rock layer in the range from the fractured sandstone layer to the lower critical layer. The working resistance of the support increases with the increase of the thickness and the breaking length of straight sandstone roof. When the breaking length of the roof reaches a certain extreme value, the support crushing accidents will occur. Managing roof with compulsive roof caving method can reduce the intensity of rock pressure in the stope, and the working face can be safely stoped, which provides a certain reference for similar conditions.